Jewelry made with brass, copper, and sterling silver naturally oxidize over time, developing a beautiful patina that is prized by some collectors. 

To restore your jewelry piece's original shine, clean with a soft cloth or jewelry polishing cloth such as Sunshine. You can also use a natural, non-toxic polish using a mixture of equal parts lemon juice and vinegar, combined with enough baking soda to form a paste. Another non-toxic cleaning option is opaque toothpaste and a soft toothbrush. 

With either cleaning solution, rinse the paste off, and dry your jewelry immediately. Do not use cleaning solutions directly on any stones on your jewelry. Never use bleach, ammonia, alcohol or acetone to clean your jewelry.

When wearing brass or silver jewelry directly on the skin, normal oxidation can result in a temporary, non-toxic skin discoloration that is easily washed off with soap and water.

Apply perfumes, hair sprays before donning your jewelry and when not wearing your jewelry, it is best to store it in a cool, dry place or in small plastic or cloth bags to minimize exposure to oxidation-causing air and humidity.